Light-Induced Thermal Gradients in Ruthenium Catalysts Significantly Enhance Ammonia Production.

Journal Article (Journal Article)

Industrial scale catalytic chemical synthesis demands both high reaction rates and high product yields. In exothermic chemical reactions, these conflicting objectives require a complex balance of optimized catalysts, high temperatures, high pressures, and multiple recycling steps, as in the energy-intensive Haber-Bosch process for ammonia synthesis. Here we report that illumination of a conventional ruthenium-based catalyst produces ammonia with high reaction rates and high conversion yields. Indeed, using continuous wave light-emitting diodes that simulate concentrated solar illumination, ammonia is copiously produced without any external heating or elevated pressures. The possibility of nonthermal plasmonic effects are excluded by carefully comparing the catalytic activity under direct and indirect illumination. Instead, thermal gradients, created and controlled by photothermal heating of the illuminated catalyst surface, are shown to be responsible for the high reaction rates and conversion yields. This nonisothermal environment enhances both by balancing the conflicting requirements of kinetics and thermodynamics, heralding the use of optically controlled thermal gradients as a universal, scalable strategy for the catalysis of many exothermic chemical reactions.

Full Text

Duke Authors

Cited Authors

  • Li, X; Zhang, X; Everitt, HO; Liu, J

Published Date

  • March 2019

Published In

Volume / Issue

  • 19 / 3

Start / End Page

  • 1706 - 1711

PubMed ID

  • 30721079

Electronic International Standard Serial Number (EISSN)

  • 1530-6992

International Standard Serial Number (ISSN)

  • 1530-6984

Digital Object Identifier (DOI)

  • 10.1021/acs.nanolett.8b04706


  • eng